This application relates to a lancet cartridge suitable for use with a lancing device by a diabetic, or other user, to obtain small samples of blood, interstitial fluid, or tissue from the fingers, forearm, or other body portions. The invention also relates to an improved lancing device comprising the lancet cartridges of the present invention.
Lancing devices are well known. Most include an outer casing, a lancet (e.g. a needle or a blade), a priming mechanism to produce and store potential energy (usually in a coil spring), and a trigger to release the stored energy to produce a lancing motion of the lancet with a hammer. Some also include a cap to cover the lancet needle in order to preserve sterility prior to use as well as helping avoid unintended skin piercing with the lancet prior to and after use. More complex lancing devices may even contain motor driven lancets that are extended and retracted by a computer driven process. Lancing devices may be designed to receive a lancet cartridge which preferably is a disposable part that includes one or more lancets. These lancet cartridges typically have the lancets disposed in a base or housing that is adapted to fit within and be removable from a lancing device that allows a hammer to strike and move the lancet in a lancing motion
Lancing devices have many uses, but the most common use is by diabetic patients to draw blood and to monitor their blood sugar levels. It would not be unusual for a diabetic patient to need to use such a device several times a day. Many of these patients are elderly and may not have the coordination and dexterity required to manipulate a complex lancet device. Most patients would desire the process for using a lancet device to be as simple, painless, and quick as possible.
Methods for using a traditional lancing devices typically start with a user removing a cap which may cover the lancet's pointed end and manually loading the lancet into lancing device. Next, the lancing device is primed by either pressing a plunger or pulling on a priming mechanism. A trigger is then pulled/pushed to release the stored potential energy and the lancet carriage is propelled forward to pierce the skin of a patient. When the lancing process is complete, the user is required to disassemble the lancing device for safe disposal of the lancet. Unfortunately, this process often includes removing the unprotected lancet while running the risk of unintentional lancing. A special container like a “sharps” container would need to be used for disposal of the unenclosed sharp lancet needle. It would not be unusual for a user to perform an additional step of loading a new lancet in order to save preparation time for the lancet device's next use.
Several improvements have been made to the traditional lancet device. These improvements include:                Lancet cartridges which allow several lancets to be loaded into a single casing at one time (see U.S. Pat. No. 6,472,220).        Complex mechanical means for retracting used lancets back into the casing, such as springs (see U.S. Pat. Nos. 6,071,294 and 6,651,989).        Motorized means for retracting used lancets back into the casing (see US Patent Application Pub. No. 2003/0212424).        Removable and pierceable sterile covers for the lancet needles (see US Patent Application Pub. No. 2003/0153939 and U.S. Pat. No. 5,741,288).        
However, these improvements share the major drawback of increasing the part count of a lancing device. Increasing the part count, in turn, increases manufacturing costs, increases the opportunity for defects and malfunctions, and decreases the ease of use of the device. Therefore, there is a need for lancing devices which have a simple design, a low part count, and a low opportunity for defects and malfunctions; while being easy to use and offering improvements such as multiple lancets in one cartridge and a means for safely retracting the lances back into a protective casing after each use.